My white Apple Watch band is turning green, how do I get rid of it?

My Apple Watch band suddenly started turning green at some point, even though I’ve had it for years I feel like I would’ve noticed a green tint much sooner. So I replaced the band with the replacement that came in the box and after a week the green tint was already back.

It’s embarrassing to wear a green Apple Watch because it looks dirty, anyway I can clean it? I tried hot water, and rubbing alcohol (90% or something) but it did nothing.